Kinetics in Mg-based hydrogen storage materials: Enhancement and mechanism

Large-vscale hydrogen production and storage technologies: Current status and future directions

Molybdenum sulfide (MoS2) has attracted great interest as a promising non-precious-metal catalyst candidate to replace the precious-metal Pt catalysts for the hydrogen evolution reaction (HER). Nevertheless, the catalytic efficiency of MoS2 is significantly restricted by its density of catalytic active sites and inert basal plane. In this work, we have designed a facile one-pot solvothermal method to synthesize porous 1T-MoS2 that is integrated with atomic doping of Cu atoms. The as-prepared Cu@MoS2 sample exhibits enhanced HER performance with a low overpotential of 131 mV at the current density of 10 mA/cm2, a small Tafel slope of 51 mV/dec and as well as a good long-term stability. Enhanced HER performance can be ascribed to the synergistic effect of 1T-MoS2 metallic phase, single atom Cu doping and numerous sulfur vacancies. Theoretical calculations indicates that the adsorption energy of Cu atom on 1T-MoS2 surface (−3.68 eV) is much higher than that on 2H-MoS2 surface (−1.94 eV), moreover, the Cu atom adsorbed on the surface of the 1T-MoS2 has larger charge transfer (−0.38e), which can be contributed to further enhance HER performance of 1T-MoS2.

One-pot synthesis of porous 1T-phase MoS2 integrated with single-atom Cu doping for enhancing electrocatalytic hydrogen evolution reaction

Progress and Trends in Magnesium-Based Materials for Energy-Storage Research: A Review

Ruthenium supported on ZIF-67 as an enhanced catalyst for hydrogen generation from hydrolysis of sodium borohydride

Hydrogen generation by hydrolysis of MgH2 and enhanced kinetics performance of ammonium chloride introducing

Hydrogen production via hydrolysis of Mg-oxide composites

Hydrogen generation is one of the enabling technologies for realization of hydrogen economy. In this study, we developed a high-performance hydrogen generation system using the transition metal Mo and its compounds (MoS2, MoO2, and MoO3) for catalyzing the hydrolysis of Mg composites in seawater. These Mg-based composites for the hydrolysis process were synthesized through a simple planetary ball mill technique. The results demonstrate that small amounts of added MoS2 could significantly accelerate and enhance the hydrolysis reaction of Mg in seawater. In particular, the Mg–10 wt% MoS2 composite releases 838 mL g−1 hydrogen in 10 min (about 89.8% of the theoretical hydrogen generation yield), and the recycled catalysts exhibit high cycle stability, which is the most significant achievement in this study. In addition, Mo, MoO2, and MoO3 also showed similar enhancement in the hydrolysis reaction of Mg. The activation energies for the hydrolysis of Mg decreased from 63.9 kJ mol−1 to 27.6 kJ mol−1, 20.4 kJ mol−1, 14.3 kJ mol−1, and 12.1 kJ mol−1 on introducing Mo, MoS2, MoO2, and MoO3, respectively. The attractive hydrolysis performance of the composites of Mg milled with Mo and its compounds in seawater may shed light on future developments of hydrogen generation technologies.

Hydrogen generation via hydrolysis of magnesium with seawater using Mo, MoO2, MoO3 and MoS2 as catalysts

Due to its relatively low cost, high hydrogen yield, and environmentally friendly hydrolysis byproducts, magnesium hydride (MgH 2 ) appears to be an attractive candidate for hydrogen generation. However, the hydrolysis reaction of MgH 2 is rapidly inhibited by the formation of a magnesium hydroxide passivation la yer. To improve the hydrolysis properties of MgH 2 -based hydrides we investigated three different approaches: ball milling, synthesis of MgH 2 -based composites, and tuning of the solution composition. We demonstrate that the formation of a composite system, such as the MgH 2 /LaH 3 composite, through ball milling and in situ synthesis, can improve the hydrolysis properties of MgH 2 in pure water. Furthermore, the addition of Ni to the MgH 2 /LaH 3 composite resulted in the synthesis of LaH 3 /MgH 2 /Ni composites. The LaH 3 /MgH 2 /Ni composites exhibited a higher hydrolysis rate—120 mL/(g·min) of H 2 in the first 5 min—than the MgH 2 /LaH 3 composite— 95 mL/(g·min)—without the formation of the magnesium hydroxide passivation layer. Moreover, the yield rate was controlled by manipul ation of the particle size via ball milling.

https://www.mdpi.com/1996-1073/8/5/4237/pdf

Enhanced Hydrogen Generation Properties of MgH2-Based Hydrides by Breaking the Magnesium Hydroxide Passivation Layer

Energy conversion and storage materials have received wide attention as fossil fuels are gradually running out and climate change is looming. Hexagonal boron nitride (h-BN) is not usually considered as a promising material for these applications because of its chemical inertness and poor electronic conductivity. However, through physical and chemical modification, h-BN shows tuneable properties that make it interesting for energy conversion and storage. The excellent stability and environmentally benign nature make h-BN derived materials particularly attractive for green energy applications. In this review, we survey the studies on structural and chemical properties of functionalised h-BN materials as well as their energy-related applications. Research progress in energy conversion and utilisation such as electrochemical catalysis, photocatalysis, and selective oxidative dehydrogenation is reviewed. Energy storage applications including rechargeable batteries, supercapacitors, and hydrogen storage are also presented. Finally, we discuss the future and challenge for functionalised h-BN in energy conversion and storage.

Minghong Huang

Papers

Hydrogen generation by hydrolysis of MgH2 and enhanced kinetics performance of ammonium chloride introducing

Hydrogen production via hydrolysis of Mg-oxide composites

Hydrogen generation via hydrolysis of magnesium with seawater using Mo, MoO2, MoO3 and MoS2 as catalysts

Enhanced Hydrogen Generation Properties of MgH2-Based Hydrides by Breaking the Magnesium Hydroxide Passivation Layer

Functionalised hexagonal boron nitride for energy conversion and storage